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Transcription
was caused by observers being restricted to the lee side of the pilot
house as frequently the windward side was taking heavy spray. This
effectively limited the angle of observation; created a blind spot of
90-135 degrees, i.e., the horizon was cut by one-third. Also due to
the fast, erratic, and severe motion of the vessel in even moderate
seas the observer is not able to use field glasses extensively to
scan the horizon. This greatly lessens his radius of visibility
which in turn causes him to record fewer birds.
Were heavy seas (10+ ft) encountered during a survey on these
vessels, observations would have to be secured as all hatches are
then secured as green water covers the pilot house. Even in more
moderate seas if the vessel is headed directly into the sea the same
"wet" conditions result.
Over 826 miles and 82.8 hours of diurnal observation, 390 birds
of 13 species* were recorded. One bird (a Shoveler) was collected.
The low number of land birds recorded is thought to indicate lack of
attraction to the small vessel. However it is possible this marks the
end of their migration/dispersion movements.
Synoptic highlights:
1) High numbers of migrating Sooty Shearwaters.
2) Increase in "Leach's" Storm Petrel numbers over last survey
and their apparent southern migration.
3) Continued low number of phalaropes.
4) Only one land bird recorded.
5) Few marine mammals recorded.
Black-footed Albatross 40
The number of albatross recorded on this cruise compares favor-
ably with that of the last three cruises. This strongly suggests
that albatross do follow small vessels as readily as they do larger
vessels. (the previous three surveys were taken from a 400+ ft. vessel).
There is no apparent explanation for the occurrence of the 14
recorded albatross in sector 4.
On 34 of the total 40 albatross, rump color was recorded; the
breakdown follows:
Dark rumped 28 (82 %)
White rumped 4 (12 %)
Mottled rump 2 (6 %)
*Albatross are not included in either of these totals.